This would seem to contradict the way R Avigdor Miller is quoted, Rashi says once they hated Yosef which was admittedly a Gnus, it was then a Shvach that they at least didn’t act falsely.

Rashi’s mekor is a medrash there (BR 84:9) which contrasts the Shvotim to Avsholom who was capable of acting differently to how he really felt (Maharzav). The Matnos Kehuna calls this geneivas daas; the Yefei Toar calls it chanufa.